Aqueous structurant premixes comprising a non-polymeric, crystalline, hydroxyl-containing structuring agent, such as hydrogenated castor oil, have been used to structure and thicken liquid compositions. While the non-polymeric, crystalline, hydroxyl-containing structuring agent can be melted and directly dispersed into a liquid composition, the structuring agent is usually first formed into a premix in order to both improve processibility, and to improve structuring efficacy. Hence, the molten structuring agent is generally first emulsified in water, and then crystallised to form an aqueous structuring premix. The resultant aqueous structuring premix is then added to a liquid composition (see for example, WO2011031940).
In recent years, liquid compositions, for use around the household, have increased in complexity, comprising a wide variety of polymers, and particulates, such as deposition aids, soil release polymers, microcapsules, perfume droplets and other oils, in addition to typical ingredients such as surfactants. Such additives provide a variety of benefits, such as better stain removal and stain repellence, care benefits such as fabric softening or skin protection, and improved aesthetics, including longer lasting freshness. The result is a liquid composition with a complex balance of hydrophilic and hydrophobic ingredients. Changes in formulation, and even level changes arising from process variation, result in changes in the hydrophilic-hydrophobic balance, as well as changes in the ionic strength.
In order to account for process variations, and other variations in ingredient levels, a higher level of structuring premix must be added, in order to ensure the desired minimum viscosity and level of structuring. This is particularly of concern for liquid compositions comprising suspended particulates or droplets, since insufficient low shear viscosity quickly results in settling or rising of the particulates or droplets, depending on the density difference. In addition, since such structuring premixes are aqueous, they result in additional water being introduced into the liquid composition. This is of particular concern for low water liquid compositions, such as those that are to be encapsulated in a water-soluble film to form unit-does articles.
Therefore, a need remains for an aqueous structuring premix, comprising a non-polymeric, crystalline, hydroxyl-containing structuring agent, having improved structuring efficacy, particularly at low shear rates. By improving the structuring efficacy, less of the structuring premix needs to be added, to ensure the desired minimum viscosity and level of structuring. Having a more efficacious aqueous structuring premix also means that less of the structuring premix needs to be added into an essentially non-aqueous liquid composition, in order to achieve the desired level of structuring. Hence, less water is introduced with the aqueous structuring premix, into such non-aqueous liquid compositions.